Fitting with draw mechanism

ABSTRACT

A fitting includes a hollow body, a sealing member, and a draw mechanism. The fitting mechanism includes a primary actuation element coupled with the body at a first end, and a plurality of secondary actuation elements coupled to the sealing member. The plurality of secondary actuation elements are positioned in an interior of the hollow body and circumferentially spaced from each other. The plurality of secondary actuation elements are also engaged with the primary actuation element such that actuation of the primary actuation element draws the plurality of secondary actuation elements axially towards the opening at the first end of the hollow body thereby translating the sealing member from an open position to a sealing position.

BACKGROUND

Technical Field

The present disclosure relates to fittings, such as pipe couplings, pipeconnectors, and pipe end caps.

Description of the Related Art

The waterworks, oil, gas, and chemical industries generally employ pipesor other hollow bodies to transport water and other fluids. Fittings arestructural elements that are typically employed to mechanically coupleindividual pipes or other hollow bodies to other system components. Forexample, a fitting can act as a connection component in conjunction witha valve, a hydrant, or a flange end. In addition, some pipes include anintegrated fitting type structure on one end to facilitate coupling.Fittings are installed in both above ground and below groundapplications. For example, they can be used in manufacturing plants fora variety of applications, including on conduit, such as electricalconduit or on heating, ventilation, and air conditioning applications.The materials used for pipes or other hollow bodies, such as conduits,can vary depending on the application. As such, particular fittings havebeen developed for use with particular materials, such as steel, castiron, cement, plastic, and other kinds of materials.

The size of the pipe or other hollow body can also vary depending on theapplication. Accordingly, fittings have been developed that flexiblycouple hollow bodies having different diameters. These fittingstypically rely on adjustable seals.

One type of conventional fitting is a pipe coupling that is configuredto couple pipes of varying size includes a series of parallel boltsdistributed circumferentially around a cylindrical body adapted toreceive the pipe. In order to achieve a seal, the bolts pull a ring, onthe end of the fitting, inwardly to wedge a seal between the pipe, thefitting body and the ring, from the outside toward the inside.

Another aspect of pipe coupling relates to axial restraint of the pipesto prevent de-coupling. Some conventional restraint systems includegrippers that are wedged between the pipe coupling and the pipe toprevent axial translation of the pipe relative to the coupling. In somepipe couplings, the grippers are teeth that are embedded as part of aseal. In other conventional pipe couplings, axial restraint is achievedwith a series of lugs that are located separate from a sealing gasketand are arranged circumferentially around a pipe in a ring. Radiallytightening an individual bolt associated with each respective lugsecures the lugs to the pipe to create the desired restraint.

Other conventional couplings employ a band-clamp that can be radiallytightened about the pipe. These couplings can employ, in one example,steel bands or rings that surround the pipe to achieve restraint.

BRIEF SUMMARY

It has been recognized that conventional fittings, such as pipecouplings, that employ a series of parallel bolts can be problematic fora number of reasons. For example, a worker who installs a pipe couplingon-site in a ditch will need to tighten the series of boltsincrementally around the circumference of the coupling in order for theseals to be seated properly. One advantage of reducing the number ofbolts needed for a coupling is that it tends to be quick and easy toinstall, in lieu of the larger number of bolts that are typical tosystems that pull a ring toward the fitting body and compress the seal.

In one embodiment, a fitting of the present disclosure includes a drawmechanism that pulls an annular seal axially outward to form aneffective seal with pipes of varying sizes and materials. The fittingincludes a hollow body that includes an opening at a first end. Asealing member is positioned on an interior surface of the hollow body.The draw mechanism includes a primary actuation element coupled with thehollow body at the first end and a plurality of secondary actuationelements coupled to the sealing member. The plurality of secondaryactuation elements are positioned in an interior of the hollow body andcircumferentially spaced from each other. The plurality of secondaryactuation elements are engaged with the primary actuation element suchthat actuation of the primary actuation element draws the plurality ofsecondary actuation elements axially towards the opening at the firstend of the hollow body, thereby translating the sealing member from anopen position to a sealing position.

In a further embodiment, the fitting can include a gripping elementcoupled to one of the plurality of secondary actuation members such thatthe gripping element is moved axially towards the opening at the firstend of the hollow body and radially inward towards the longitudinal axisof the hollow body from an open position to an engaged position byactuating the primary actuation element. The gripping element can abutthe sealing member.

In one embodiment, the gripping element is not fixedly attached toeither of the one of the plurality of secondary actuation members or thesealing member. This advantageously can allow for the gripping elementto float relative to the hollow body and accommodate varying pipe sizesand cross-sectional shapes.

In another embodiment, the fitting includes a plurality of grippingelements. The number of gripping elements may be less than the number ofsecondary actuation elements. In other example, there may be moregripping elements than secondary actuation elements, depending on howthe gripping elements are structured.

The primary actuation element may be rotatably mounted to an exteriorsurface on the first end of the hollow body. The first end of the hollowbody may include a plurality of circumferentially spaced tapered tabsthat converge towards the longitudinal axis at the first end. Adjacentones of the tabs are separated in the first circumferential direction bylongitudinally extending slots. The secondary actuation members can eachextend through a respective one of the longitudinally extending slots.

In one embodiment, the primary actuation element includes a plurality ofsloped surfaces and each one of the secondary actuation elements isengaged with a respective one of the plurality of sloped surfaces.

In one embodiment, the primary actuation element is rotatably coupledwith the hollow body at the first end and rotation of the primaryactuation element in a first circumferential direction with respect tothe longitudinal axis of the hollow body draws the plurality ofsecondary actuation elements axially towards the opening at the firstend of the hollow body thereby translating the sealing member from anopen position to a sealing position.

In one embodiment, the hollow body is coupled to the primary actuationelement such that the primary actuation element is rotated in the firstcircumferential direction by actuating at least one bolt. The bolt canextend from a first bolt receiver that extends from the hollow body to asecond bolt receiver that extends from the primary actuation element.The first and second bolt receivers are positioned such that actuatingthe bolt causes the primary actuation element to rotate in the firstcircumferential direction. Actuating the bolt can include tightening thebolt so as to move the second bolt receiver towards the first boltreceiver.

In another embodiment, a fitting includes a hollow body, an annularsealing member, and an actuation mechanism. The hollow body includes anopening at a first end. The annular sealing member is positioned on aninterior surface of the hollow body. The actuation mechanism isconfigured to draw the sealing member axially towards the first end ofthe hollow body and radially inward towards a longitudinal axis of thehollow body by actuating at least one bolt that is coupled to the hollowbody and the actuation mechanism. The at least one bolt extendssubstantially transverse to the longitudinal axis of the hollow body.

The fitting can also include a plurality of restraining elements thatare circumferentially arranged on the interior surface of the hollowbody. The plurality of restraining elements can be arranged axiallybetween the sealing member and the first end of the hollow body.

The actuation member can include a ring rotatably mounted to the hollowbody and a plurality of follower elements. Each of the follower elementsare coupled to the annular sealing ring. The at least one bolt can becoupled to the ring such that actuating the at least one bolt causes thering to rotate in a circumferential direction with respect to the hollowbody, and the plurality of follower elements engage the ring such thatrotation of the ring causes the plurality of follower elements totranslate towards the first end of the hollow body.

In another aspect, a plurality of restraining elements can be arrangedcircumferentially on the interior surface of the hollow body betweenadjacent follower elements and axially between the sealing member andthe first end of the hollow body.

In one embodiment, the ring can include a plurality of cam surfaces thatvary in axial length along the circumferential direction. Each one ofthe follower elements can include an engagement portion that engages arespective one of the cam surfaces of the ring. The engagement portionof each of the follower elements can be a hook. The hook can include asloped portion that corresponds in shape to an axial end surface of thecam surfaces of the ring.

In one embodiment, the ring can be mounted to an external surface of thehollow body. The first end of the hollow body can include a plurality ofcircumferentially spaced slots that extend through the hollow body fromthe external surface of the hollow body to the internal surface of thehollow body and that extend substantially parallel to the longitudinalaxis of the hollow body. The hook on each one of the follower elementsextends through a respective one of the slots in the hollow body.

The first end of the hollow body can include a first taper that extendstowards the longitudinal axis of the hollow body. The cam surfaces ofthe ring can include a second taper that is complementary to the firsttaper.

In one embodiment, the ring can include a first bolt receiver, thehollow body can include a second bolt receiver, and the single boltextends through the first and second bolt receivers.

In one embodiment, the annular sealing member includes a substantiallytrapezoidal cross-section.

In one embodiment, each follower element includes a stem that extendsaxially from the engagement portion to a base portion. The base portionis coupled to the annular sealing member. Each of the restrainingelements can include a recess that extends through the restrainingelement in a direction substantially parallel to the longitudinal axisof the hollow body, and a stem of a respective one of the followerelements can be seated in the recess. Each of the recess of eachrestraining element can includes a first ramp portion that iscomplementary to a second ramp portion of the stem of a correspondingone of the follower elements.

In another embodiment, a fitting has a hollow body or barrel portionwith at least one open end for receiving the end of a pipe. The barrelportion has an inside or interior tapered surface that converges aroundan axis, in a direction moving toward the open end of the barrel portion(from inside the barrel portion toward the outside). An annular gasketor seal can be located in the barrel portion between the tapered surfacejust described and the pipe. The annular seal has an outer surface thatslides against, and is in contact with, the tapered surface; and aninner surface that similarly contacts and surrounds the pipe. A drawmechanism pulls the annular seal axially outwardly, against the taperedsurface, and wedges the seal between the tapered surface and pipe. Inthis example, the wedging action works from inside in a direction towardthe outside, rather than outside-in.

The draw mechanism can be mechanically linked to a rotatable boltmechanism that is aligned substantially perpendicularly relative to theseal's axial path of travel. The mechanical linkage translates theperpendicular tightening force of the bolt mechanism into a pullingforce that parallels the seal's path of travel, thus wedging the seal asdescribed above.

The fitting of this embodiment can be built with or without restraint.To achieve restraint, gripper members can be positioned on an annularside of the seal that normally faces the open end of the barrel portion(or facing toward the outside). As the draw mechanism pulls the sealoutwardly, the gripper members are pulled outwardly at the same time,ahead of the seal, to wedge the seal and gripper members at the sametime (between the barrel portion and pipe).

In one embodiment, the fitting may include a multi-layer seal that has aremovable layer. The removable layer can further facilitate the range ofpipe diameters that are compatible with the fitting withoutnecessitating a change in the size of the barrel portion. For example,removal of the seal's inner layer can allow the seal to fit around alarger pipe.

In one embodiment, the draw mechanism includes a rotatable end ring thatsurrounds the barrel portion's open end. The end ring has slopedsurfaces distributed around it. An annular seal can carry a plurality ofdraw linkages, each one having an inner portion connected to the annularseal and an outer portion that engages with one of the sloped surfacesof the end ring—in sliding contact with the sloped surface. As the endring rotates, the sloped surfaces draw the linkage axially outwardly.This, in turn, draws the annular seal outwardly (with the grippermembers). In some examples, counter-rotation of the end ring releases orrelaxes the draw linkage and seal. The collection of draw linkages andsloped surfaces can cooperate to draw the seal outwardly in a generallysymmetric fashion.

The individual gripper members can have pointed gripper teeth that areoriented or directed radially inwardly toward the pipe. In oneembodiment, there is one gripper member corresponding to each drawlinkage. In other embodiments, the number of grippers is less than thenumber of draw linkages. As described above, the collection of grippermembers are pulled axially outwardly, as the draw mechanism pulls andslides the seal axially outwardly.

In one embodiment, the end ring rests on an outside annular shoulder ofthe barrel portion. In this example, annular shoulder of the barrelportion also has a partly tapered surface that symmetrically convergesaway from the annular shoulder. However, as will be readily apparent toone having ordinary skill in the art upon review of the presentdisclosure in its entirety, the end ring can be coupled to the barrelportion in a number of ways without departing from the spirit of thepresent disclosure.

In another aspect, the barrel portion has a plurality of draw linkageslots through which each linkage extends. These slots prevent the sealfrom rotating while it is pulled outwardly. They also enable the drawlinkages to take full advantage of the draw length provided by eachsloped section of the end ring.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the Figures, identical reference numbers identify similar elements oracts.

FIG. 1 is an isometric view of a pipe coupling system in accordance withone embodiment of the present disclosure;

FIG. 2 is an exploded view of the pipe coupling illustrated in FIG. 1;

FIG. 3 is a side cross-sectional view illustrating the operation of thepipe coupling illustrated in FIGS. 1 and 2;

FIG. 4 is an enlarged sectional view of the seal section illustrated inFIG. 3 in an open configuration;

FIG. 5 is an enlarged sectional view of the seal section illustrated inFIG. 3 in an engaged configuration;

FIG. 6 is a view of an end ring in one embodiment;

FIG. 7 is a view of a gasket assembly with grippers in one embodiment;

FIG. 8 is a back-side view of a draw linkage that makes up part of thegasket assembly, looking radially outward from the center of the gasketassembly illustrated in FIG. 7;

FIG. 9 is a view of a draw linkage that makes up part of the gasketassembly, looking radially inward towards the center of the gasketassembly illustrated in FIG. 7;

FIG. 10 is a view of a draw linkage that makes up part of the gasketassembly sectioned through a draw hook portion at the end of the linkage

FIG. 11 is a sectioned, pictorial view of a section of the gasketassembly illustrated in FIG. 7;

FIG. 12 is a pictorial view of the inner portion of the draw linkageillustrated in FIG. 11;

FIG. 13 is a pictorial view of the outer portion of the draw linkageillustrated in FIG. 11;

FIG. 14 is an end view of the pipe coupling illustrated in FIG. 1, withthe pipe coupling illustrated in an “open” or untightened condition;

FIG. 15 is an end view of the pipe coupling illustrated in FIG. 1, withthe pipe coupling illustrated in a closed or “tightened” condition;

FIG. 16 illustrates an embodiment of a seal that has multiple layers foradjusting to different pipe sizes;

FIG. 17 illustrates a multi-layer seal;

FIG. 18 is a sectional view of the multi-layer seal illustrated in FIGS.16 and 17;

FIG. 19 illustrates the multi-layer seal of FIG. 17 with the inner layerremoved;

FIG. 20 illustrates a coupling that includes less grippers than drawhooks;

FIG. 21 illustrates a coupling that includes two bolts on either end;and

FIG. 22a illustrates a coupling with grippers arranged between adjacentdraw hooks;

FIG. 22b is a view of the gasket assembly of the coupling of FIG. 22a ;and

FIG. 22c is a view of two grippers and a draw hook assembly of thecoupling of FIG. 22 a.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments of theinvention. However, one skilled in the art will understand that theinvention may be practiced without these details.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, such as“comprises” and “comprising” are to be construed in an open, inclusivesense, that is, as “including but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its broadest sense, that is as meaning “and/or”unless the content clearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are forconvenience only and do not interpret the scope or meaning of theembodiments.

I. System Overview

In one aspect, a fitting of the present disclosure can achieve bothsealing and restraint over a wide range of pipe sizes, including sizesranging from Iron Pipe Size (IPS) to Ductile Iron (DI) and beyond. Inone example, the fitting is internally restrained to a hollow body andbacked by a gasket seal. Segmented restraining elements are coupled to acircumferential elastomeric gasket positioned inside a cone shapedsurface of the hollow body. As the restraining elements are drawn downthe cone by a draw mechanism, they contract, along with the gasket, downon to a pipe achieving both sealing and restraint on the pipe. Asinternal pressure increases within the pipe after the fitting isinstalled, the gasket and restraining elements are further energized toseal and restrain the pipe.

Advantageously, the fitting of the present disclosure accommodates avariety of field conditions, such as dirt, pipe corrosion, pipevariability and pipe deflection relative to the fitting. For example,depending on the working environment, it can be difficult to ensure thata pipe and a fitting, such as a pipe coupling, are entirely axiallyaligned when the pipe coupling is installed. Instead, the longitudinalaxis of the pipe may be deflected at an angle relative to thelongitudinal axis of the coupling during installation. This misalignmentmay result from, for example, settlement, the inaccuracies of pipeinstallation, and tight working conditions in a trench. The fitting ofthe present disclosure can, in some examples, achieve consistentcoupling, restraint, and sealing even when the longitudinal axis of thepipe is deflected by, for example, up to 8° relative to the longitudinalaxis of the coupling. This is particularly advantageous to make upmis-alignment of pipe which is typical to most applications.

The fitting of the present disclosure also improves the ease ofinstallation. Conventional fittings, such as pipe couplings, thatachieve both restraint and sealing typically employ a series of parallelbolts that extend in the longitudinal direction of the coupling, and aseries of bolts that extend radially from the coupling. The parallelbolts are tightened incrementally around the circumference of thecoupling in order for the seals to be seated properly. The radiallyextending bolts are then tightened to achieve restraint. This process isnot only time consuming, but can be difficult to achieve depending onthe working conditions at a particular installation site.

The fitting of the present disclosure employs a draw mechanism that can,in some examples, be operated by actuating a single bolt that extends ina direction transverse to the longitudinal direction of the pipe. Thisdesign allows for easier access to the bolt during installation, reducesthe amount of time for installation, and reduces the amount of spaceneeded for an installation. Reducing the amount of space required forinstallation means that the trench dug to accommodate the fitting neednot be as large as for conventional pipe couplings. The single boltdesign offers an added element of safety for the installer as they areno longer required to work in the bottom of the ditch. All of thesebenefits lead to cost savings and improved ease at the time ofinstallation. Other examples can employ actuation elements other than abolt, or multiple bolts that extend transverse to the longitudinaldirection of the fitting.

Not only does the draw mechanism of the present disclosure allow therestraint mechanism to achieve restraint for pipes with a wide range ofoutside pipe diameters, but the draw mechanism allows the restraint tobe easily disengaged, even after the pipe has been pressurized and thendepressurized.

It has been further recognized that some conventional restraint systemscan act to disengage the gasket used in sealing. By contrast, thesealing and restraint aspects of the coupling system of the presentdisclosure work together and, in some examples, can be further energizedby pressurization in the pipe.

FIGS. 1-3 provide an overview of a fitting according to one exampleembodiment of the present disclosure. In this example, the fitting is apipe coupling system. FIG. 1 is an isometric view of a fitting 10 inaccordance with one embodiment of the present disclosure. FIG. 2 is anexploded view of the fitting 10 illustrated in FIG. 1. FIG. 3 is a sidecross-sectional view illustrating the operation of the fitting 10illustrated in FIGS. 1 and 2.

In this example, the fitting 10 includes a generally cylindrical andtubular body or barrel sleeve 12. Each end of the sleeve 12 includes anopening into which a pipe can be inserted. The barrel sleeve 12 is ahollow body that provides a fluid passageway that connects the ends oftwo pipes together. However, the inventive concepts of the presentdisclosure are also applicable to other fittings that include hollowbodies. For example, fittings of a “T” coupling, a single-end coupling,or an end cap, depending on the application all include hollow bodiesthat are encompassed within the present disclosure. In other examples,the fitting can be employed as a connection component in conjunctionwith a valve, a hydrant, or a flange end, all of which include hollowbodies. Pipes may also be configured so that one or both ends includethe disclosed fitting configuration. For example, a pipe can include anintegrated fitting type structure on one or both ends to facilitatecoupling. The fitting of the present application can be employed in avariety of applications and is not limited to waterworks. For example,the fitting of the present disclosure can be employed in connectionsused in the oil, gas, or chemical industries. The fitting of the presentapplication is applicable to installations intended for placement bothabove ground and below ground. For example, the fitting can be used inmanufacturing plants for a variety of applications, including onconduit, such as electrical conduit or on heating, ventilation, and airconditioning applications.

An end ring 20, several lugs 50, several grippers 46, a gasket 44, and asingle bolt 26 are installed on each end of the sleeve 12. The singlebolt 26 extends through two bolt receivers 36, 38 that are respectivelypositioned on the end ring 20 and the sleeve 12.

The end ring 20 is rotatably mounted on an end of the sleeve 12. As seenin FIGS. 1 and 3, the lugs 50 connect the gasket/gripper assembly 18 tothe end ring 20. These lugs 50 are positioned within slots 80 in thesleeve 12. The slots 80 prevent the lugs 50 from rotating with respectto the sleeve 12, but allow longitudinal motion along the axis of thecoupling.

FIGS. 3-5 show how the coupling engages a pipe. FIG. 3 illustrates thecoupling of two pipes 66 a and 66 b, and FIGS. 3 and 4 respectivelyillustrate a fitting in open and closed states relative to a pipe 66.The right side of FIG. 3 illustrates a fitting in an open state in whichit is disengaged from a portion of a pipe 66 b that is adjacent to aninner-most end 70 b of the pipe 66 b. The left side of FIG. 3illustrates the fitting in a coupled state, in which it is engaged witha portion of a pipe 66 a that is adjacent to an inner-most end 70 a ofthe pipe 66 a. Actuating the end ring 20 translates rotational motion ofthe end ring 20 into longitudinal movement of the lugs 50 that drawsboth the gasket 44 and the gripper elements 46 down the face of aninternal cone of the sleeve 12. In greater detail, tightening the bolt26 causes the end ring 20 to rotate with respect to the sleeve 12. Asthe end ring 20 rotates, the lugs 50 ride up along ramp sections 30 onthe end ring 20, effectively pulling the lugs out axially away from thesleeve 12, while simultaneously drawing the lugs 50 radially inwardtowards the center axis of the pipe.

The longitudinal movement of the lugs 50 draws the combinedgripper/gasket assembly 18 down into contact with the pipe to effect aseal and engage the restraints. As the lugs 50 move away from the bodyof the sleeve 12, they draw the gripper/gasket assembly 18 down theinternal cone surface of the sleeve 12 towards the opening in the end ofthe sleeve 12. This brings the gripper segments 46 closer together andcompresses the rubber gasket 44. The rubber gasket 44 eventually comesin contact with the outer surface of the pipe and begins to effect aseal. As the system continues to be tightened, the gasket 44 continuesto be compressed between the pipe and the sleeve 12. Tighteningcontinues until the gripper elements 46 eventually become wedged betweenthe pipe and the inner surface of the sleeve 12, thus initiating therestraint engagement. When the pipe 66 is pressurized (or the pipes 66 aand 66 b in the example in FIG. 3), the gasket is further forced downinto its sealing cavity between the pipe and the sleeve 12, and therestraints are similarly driven down to a tighter grip on the pipe, asthe internal pressure increases. However, the present disclosure is notlimited soley to fittings that are further energized with the additionof pressure. In other examples, complete engagement and sealing isachieved regardless of the pressure that flows through the pipe 66.

With this configuration, a single bolt with relatively low torque is allthat is necessary for assembly. Bolt tightening forces act to create theinitial seal and set the restraints. System internal pressure and piperetraction forces act to energize the seals and restraints beyond thisinitial set. The coupling restrains to the sleeve 12, and does not relyon bolts or end rings to support the pressure or restraint forces.

The various aspects of the coupling of the present disclosure will nowbe described in greater detail.

II. Center Sleeve

Referring to FIG. 3, the barrel sleeve 12 has an annular surface orshoulder 32 on each end. The shoulder 32 provides a resting place for asimilarly shaped annular portion 34 of the end ring 20. In this manner,the annular portion of the end ring 20 rests in sliding contact with thecorresponding annular surface 32 on the barrel sleeve such that the endring 20 is rotatable relative to the barrel sleeve 12. Although thepresent example includes an annular surface or shoulder, the presentdisclosure also encompasses other mounting structures that allow the endring to rotate relative to the sleeve 12, as will be readily apparent tothose having ordinary skill in the art upon review of the presentdisclosure in its entirety.

III. End Ring

Referring to FIG. 6, the end ring 20 has a plurality of sloped surfaces30 or ramp sections. Each sloped surface serves as a camming surfacethat tightens the gasket assembly 18 about the pipe.

The end ring 20 is turned on the coupling 10 by one of the tighteningbolts 26. The end ring 20 is preferably made with a bolt receiver 36that works in cooperation with a similar bolt receiver 38 on the barrelsleeve 12. In one embodiment, tightening the bolt acts to draw the boltreceivers 36 and 38 towards each other so as to drive the rotation ofthe end ring 20. Depending on the construction of the bolt receivers,and how the bolt is mounted thereto, loosening the bolt can also serveto drive the end ring 20 in the opposite rotational direction.

The plurality of ramp sections 30 are collectively tapered inwardly,relative to the ring's annular portion 34, so that they slope orconverge toward the center of the end ring 20. The convergence of theramp sections 30 is also illustrated at 40 in FIG. 4. The outer endopening of the barrel sleeve has a similarly shaped converging surface42 that also partly supports sliding rotation of the end ring 20, nearthe junction of the end ring's ramp sections 30 and annular portion 34.

IV. Gasket Assembly

The gasket assembly 18 will now be further described with reference toFIGS. 7-10. Referring to FIG. 7, the gasket assembly 18 includes anannular rubber gasket member 44. The gasket member 44 (or “gasket”) hasthe cross-section illustrated in FIG. 4 when it is in a relaxed or“non-tightened” condition. A plurality of gripper members 46 rest on anupper surface 48 of gasket 44. The gripper members 46 are held in anannular arrangement around the gasket 44 by draw linkages 50 that arealso distributed around the gasket 44.

Referring now to FIGS. 8-10, each draw linkage 50 has a base portion 52that is embedded in the gasket material 44, thus connecting the drawhook 50 to the gasket. Each gripper member 46 has a slot 54 that fits toand around on three sides of a stem portion 56 of each respective drawlinkage 50. This allows each gripper member 46 to be held at a specificannular position relative to the other gripping members, but with nofixed connection with either the gasket 44 or draw linkages 50, so thatthe gripper members 46 can move independently as the gasket assembly istightened about a pipe. This independent motion can allow the grippermembers to engage a variety of pipe sizes and shapes, regardless ofwhether they are perfectly round or have a degree of eccentricity.

FIG. 8 is a view that looks from the inside to the outside (radially)relative to the generally annular configuration of gasket assembly 18.Reference numeral 58 points to gripper “teeth,” which will be furtherdescribed below. FIG. 9 is a view from the outside-in (radially). Theouter surface 60 of each gripper member 46 is smooth for reasonsdescribed below. As can be seen, the slot 54 in the gripper member 46extends only partially through the lateral thickness of the grippermember for receiving the draw linkage's stem 56.

Referring now to FIGS. 7 and 10 at the same time, each draw linkage 50has an upper “hook” portion or draw hook 62. The inner part of the hook62 is sloped, as shown at 64 in FIG. 10. This sloped part 64respectively rides on one of the plurality of ramp sections 30 of an endring 20. As a consequence, when the end ring 20 is rotationally turnedby the bolt mechanism described above (i.e., by one of the twotightening bolts 26), a sliding/camming action is created between thesloped surfaces of ramp sections 30 and the sloped surfaces 64,respectively. This functions to “draw” gasket 44 outwardly, as furtherdescribed below.

FIGS. 11-13 provide further illustrations of the draw linkages 50previously described. The shape of the draw linkages 50 may varydepending on the forming method used. In FIGS. 11-13, for example, eachdraw linkage 50 is connected to a base piece 52 that is embedded in thegasket material 44. The stem portion 56 may be welded to the base piece52. Otherwise, the embodiments shown in FIGS. 11-13 is the same as theforegoing description.

V. Operation

FIGS. 4 and 5 illustrate how the various parts described above cooperateto clamp a pipe's end to the fitting 10. Referring first to FIG. 4, thepipe 66 is inserted into an open end (indicated generally at 68) of thecoupling body 10 with the inner-most end of the pipe 70 terminatingsomewhere inside barrel sleeve 12 (see FIG. 3). In other examples,depending on the type of fitting, the inner-most end of the pipe 70 mayextend through and protrude beyond the end of the fitting. The barrelportion 12 has an inside tapered surface 72. In this example, thetapered surface 72 symmetrically converges toward the coupling's openend. In other words, tapered surface 72 symmetrically converges around acenter-line axis, moving from inside the coupling in a direction towardthe outside. In this example, the outer surface 74 of gasket 44 and theouter smooth surface 60 of the gripper member 46 (previously described)has a similar slope that matches the slope of tapered surface 72.

When the end ring 20 is “tightened” by the bolt mechanism (i.e., drivenin rotation by tightening bolt 26), the sloped ramp sections 30 on theend ring 20 draws the draw hooks 62 axially outwardly, in the directionindicated by arrow 76 in FIG. 5. This likewise draws or pulls the gasket44 and gripper members 46 against the inside tapered surface 72 of thebarrel sleeve and forces the gasket 44 and gripper members 46 againstthe pipe 70, thus wedging gaskets and grippers between the sleeve andpipe. In this respect, the gasket 44 slides from the inside, toward theoutside, against the converging, tapered surface of the barrel sleeve 12and is restrained between the inner wall 72 of the barrel and the outerwall 78 of the pipe, thereby compressing the gasket 44 in the mannershown in FIG. 5. Each gripper member 46 is similarly drawn into therestrained position between barrel and pipe surfaces 72, 78, with thegripper teeth 58 of each gripper member being driven into the outersurface of the pipe.

As is best seen in the exploded view, FIG. 2, each end 22, 24 of thepipe coupling has a plurality of slots 80 distributed around theperiphery. These slots match the location of the draw hooks 50 andaccomplish at least two functions. First, slots 80 provide sufficientdistance of travel, sometimes referred to as throw or draw, for thehooks 50 to cam against the ramp sections 30 of the end ring. Second,slots 80 prevent the gasket assembly 18 from rotating when end ring 20rotates. In other words, the combination of the draw hooks 50 fittingwithin slots 80 constrains the gasket from rotation as it is drawnoutwardly by rotation of the end ring 20. The slots 80 are sizedrelative to the draw hook stems 56 so that they may slide axiallyoutwardly, and flex, as needed, during the course of the drawing actionjust described.

Overall, the clamping assembly described above creates a unique drawmechanism that pulls the gasket 44 outwardly against the taper of thebarrel portion 12 (see vector 100 in FIG. 5) and compresses or wedgesthe gasket 44 with a compressive force (see vector 102).

Referring to FIGS. 14 and 15, one of the advantages of the foregoingdesign is that it is easy to use. Because of the gripper members 46, aperson skilled in the art would recognize the pipe sealing actiondescribed above as a “restraint” system where a resilient seal (withgripper teeth) is wedged between the pipe and the pipe coupling. In thepresent design, the tightening action is accomplished via one bolt ateach end that is orientated cross-wise to the coupling's axis ofsymmetry. The force of tightening the bolt is perpendicularlytransferred to the gasket 44 via the clamping assembly just described.However, mechanically drawing the seal or gasket 44 with force frominside the fitting 10 toward the outside, is opposite from the wayconventional systems have worked in the past. In essence, the mechanicallinkage that transfers force from the tightening bolt mechanism isaccomplished by the combination of end ring 20 coupled to the drawlinkages 50 that ride upon sloped surfaces 30 as the end ring 20 turns.In some examples, and depending on how the nut 28 and bolt 26 aremounted to the lugs, end ring 20 rotates in one direction, or the other,depending on whether the tightening force is applied or relaxed (whichis dependent on how the nut 28 on the tightening bolt 26 is turned).

Referring now to FIG. 14, the sleeve includes a tightening bolt receiver38, and to the end ring includes a similar bolt receiver 36. These tworeceivers 36, 38 are connected by the threaded bolt 26 and nut 28. FIG.14 illustrates an “open” condition. Tightening the nut 28 causes the twobolt receivers 36, 38 to close with rotation of the nut 28 about thethreaded bolt 26, to the closed position illustrated in FIG. 15. Aspreviously described, this action rotates the end ring 20 and draws thelinkages 50 along the axially outward path that draws and wedges thegasket 44 and gripper members 46 between the sleeve's inner wall 72 andouter surface 78 of the pipe. Releasing the nut 28 allows the gasketassembly 18 to “relax” and the end ring 20 reverses its rotationaldirection.

VI. Additional Configurations

Other embodiments of the foregoing design may relate to changes in theconfiguration of the gasket assembly illustrated at 18 in FIG. 6.Referring to FIG. 16, for example, it may be possible to implement thedraw mechanism described above (translation of “perpendicular” force toan axial “draw”) without “restraint,” i.e., without using the grippermembers 46. Likewise, it is also possible to use griper members on some,but not all of the of the draw hooks. For example, FIG. 20 illustrates afitting, which in this example is a pipe coupling 10 a, that includesfewer gripper members 46 than lugs 50.

As a further change, the gasket 44, itself may be manufactured as amulti-layer, “extended range” gasket having outer and inner seal. Forexample, FIG. 18 illustrates a gasket 44a that includes an inner layer92 that can be “removable” from an outer layer 90 so as to enable thegasket 44a to adjust to different pipe diameters (see, FIG. 19). Thisprovides a certain amount of “extended” range. Otherwise, operation ofthe gasket assembly in FIGS. 16-19 remains the same as described above.

The pipe coupling described and illustrated here is a “one-bolt” systemthat uses a single tightening bolt 26 for each end ring 20. However,other couplings that include more than one bolt on each end are alsowithin the scope of the present disclosure. For example, FIG. 21illustrates a fitting 10 b that includes two bolts 26 on either end.

Further, although the tightening mechanism is described in the foregoingexamples as a bolt mechanism, other mechanisms that create aperpendicular force adequate to rotate the end ring also fall within thescope of the present disclosure.

In another example, the grippers are positioned between adjacent drawhooks. FIG. 22a illustrates a fitting 10 c that includes grippers 46 apositioned between adjacent draw hooks 50. As shown in FIG. 22b , thedraw hooks 50 are coupled to a gasket 44. The grippers 46 a may or maynot be temporarily coupled to the gasket 44 for the purpose of initialplacement during installation. For example, the grippers 46 a may betemporarily adhered to the gasket 44 to facilitate installation. FIG.22a further illustrates that the grippers 46 a may include extensions 46b that project over the draw hook 50 without directly contacting thedraw hook 50.

In another example, which is not depicted, the grippers may be anintegral part of the gasket. In this example, the drawing the gasketradially inward will also engage the grippers that are integral with thegasket.

VII. Materials and Manufacture

While there are different ways of manufacturing the parts describedabove, many of the foregoing parts, like the barrel sleeve 12 and endring 20, for example, can be cast. Gasket 44 could be made of aconventional rubber material. The gripper members 46 and draw hooks 50could be fabricated from a variety of materials, such as steel,stainless steel, or ductile iron, for example. The barrel sleeve 12 mayinclude a handle 84 which makes the coupling easier to use. As notedabove, although the fitting 10 is described here as an end-to-endcoupling, it could be configured in other ways such as a “T” coupling ora single-end coupling, depending on the application.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

1. A fitting, comprising: a hollow body that includes an opening at afirst end; a sealing member positionable on an interior surface of thehollow body; a draw mechanism including a primary actuation elementcoupleable with an exterior of the hollow body at the first end, and aplurality of secondary actuation elements coupled to the sealing member,the plurality of secondary actuation elements positioned in an interiorof the hollow body, the plurality of secondary actuation elementsengaged with the primary actuation element such that actuation of theprimary actuation element moves the plurality of secondary actuationelements towards the opening at the first end of the hollow body andradially inward toward a central longitudinal axis of the hollow body,thereby translating the sealing member from an open position to asealing position.
 2. The fitting of claim 1, further comprising agripping element coupled to one of the plurality of secondary actuationelements such that the gripping element is moved axially towards theopening at the first end of the hollow body and radially inward towardsthe longitudinal axis of the hollow body from an open position to anengaged position by actuating the primary actuation element.
 3. Thefitting of claim 2, wherein the gripping element abuts the sealingmember.
 4. The fitting of claim 3, wherein the gripping element is notfixedly attached to either of the one of the plurality of secondaryactuation members or the sealing member.
 5. The fitting of claim 1,further comprising a plurality of gripping elements, each of thegripping elements coupled to one of the plurality of secondary actuationmembers such that the plurality of gripping elements are moved axiallytowards the first end of the hollow body and radially inward towards thelongitudinal axis of the hollow body from an open position to an engagedposition by actuating the primary actuation element.
 6. The fitting ofclaim 1, wherein the first end of the hollow body includes a pluralityof circumferentially spaced tapered tabs that converge towards thelongitudinal axis at the first end, adjacent ones of the tabs beingseparated in the first circumferential direction by longitudinallyextending slots and wherein the secondary actuation members each extendthrough a respective one of the longitudinally extending slots.
 7. Thefitting of claim 1, wherein the primary actuation element includes aplurality of sloped surfaces and each one of the secondary actuationelements is engaged with a respective one of the plurality of slopedsurfaces.
 8. The fitting of claim 1, wherein the primary actuationelement is rotatably coupled with the hollow body at the first end androtation of the primary actuation element in a first circumferentialdirection with respect a the longitudinal axis of the hollow body drawsthe plurality of secondary actuation elements axially towards theopening at the first end of the hollow body, thereby dragging thesealing member from an open position to a sealing position.
 9. Thefitting of claim 8, wherein the hollow body is coupled to the primaryactuation element such that the primary actuation element is rotated inthe first circumferential direction by actuating at least one bolt. 10.The fitting of claim 8, further comprising a bolt that extends from afirst lug that extends from the hollow body to a second lug that extendsfrom the primary actuation element, wherein the first and second lugsare positioned such that actuating the bolt causes the primary actuationelement to rotate in the first circumferential direction. 11-20.(canceled)
 21. A fitting, comprising: a hollow body that includes anopening at a first end; a sealing member positionable on an interiorsurface of the hollow body; a draw mechanism including a primaryactuation element coupleable with the hollow body at the first end, anda plurality of secondary actuation elements coupled directly to thesealing member, the plurality of secondary actuation elements positionedin an interior of the hollow body, the plurality of secondary actuationelements engaged with the primary actuation element such that actuationof the primary actuation element moves the plurality of secondaryactuation elements towards the opening at the first end of the hollowbody and radially inward toward a central longitudinal axis of thehollow body, thereby translating the sealing member from an openposition to a sealing position.
 22. The fitting of claim 21, furthercomprising a gripping element coupled to one of the plurality ofsecondary actuation elements such that the gripping element is movedaxially towards the opening at the first end of the hollow body andradially inward towards the longitudinal axis of the hollow body from anopen position to an engaged position by actuating the primary actuationelement.
 23. The fitting of claim 22, wherein the gripping element abutsthe sealing member.
 24. The fitting of claim 23, wherein the grippingelement is not fixedly attached to either of the one of the plurality ofsecondary actuation members or the sealing member.
 25. The fitting ofclaim 21, further comprising a plurality of gripping elements, each ofthe gripping elements coupled to one of the plurality of secondaryactuation members such that the plurality of gripping elements are movedaxially towards the first end of the hollow body and radially inwardtowards the longitudinal axis of the hollow body from an open positionto an engaged position by actuating the primary actuation element. 26.The fitting of claim 21, wherein the first end of the hollow bodyincludes a plurality of circumferentially spaced tapered tabs thatconverge towards the longitudinal axis at the first end, adjacent onesof the tabs being separated in the first circumferential direction bylongitudinally extending slots and wherein the secondary actuationmembers each extend through a respective one of the longitudinallyextending slots.
 27. The fitting of claim 21, wherein the primaryactuation element includes a plurality of sloped surfaces and each oneof the secondary actuation elements is engaged with a respective one ofthe plurality of sloped surfaces.
 28. The fitting of claim 21, whereinthe primary actuation element is rotatably coupled with the hollow bodyat the first end and rotation of the primary actuation element in afirst circumferential direction with respect to the longitudinal axis ofthe hollow body draws the plurality of secondary actuation elementsaxially towards the opening at the first end of the hollow body, therebydragging the sealing member from an open position to a sealing position.29. The fitting of claim 28, wherein the hollow body is coupled to theprimary actuation element such that the primary actuation element isrotated in the first circumferential direction by actuating at least onebolt.
 30. The fitting of claim 28, further comprising a bolt thatextends from a first lug that extends from the hollow body to a secondlug that extends from the primary actuation element, wherein the firstand second lugs are positioned such that actuating the bolt causes theprimary actuation element to rotate in the first circumferentialdirection.
 31. A fitting, comprising: a hollow body that includes anopening at a first end; a sealing member positionable on an interiorsurface of the hollow body; a draw mechanism including a primaryactuation element coupleable with the hollow body at the first end, anda plurality of secondary actuation elements coupled to the sealingmember such that movement of the plurality of secondary actuationelements towards the opening and radially inward pulls the sealingmember from an open position to a sealing position, the plurality ofsecondary actuation elements positioned in an interior of the hollowbody, the plurality of secondary actuation elements engaged with theprimary actuation element such that actuation of the primary actuationelement moves the plurality of secondary actuation elements towards theopening at the first end of the hollow body and radially inward toward acentral longitudinal axis of the hollow body.
 32. The fitting of claim31, further comprising a gripping element coupled to one of theplurality of secondary actuation elements such that the gripping elementis moved axially towards the opening at the first end of the hollow bodyand radially inward towards the longitudinal axis of the hollow bodyfrom an open position to an engaged position by actuating the primaryactuation element.
 33. The fitting of claim 32, wherein the grippingelement abuts the sealing member.
 34. The fitting of claim 33, whereinthe gripping element is not fixedly attached to either of the one of theplurality of secondary actuation members or the sealing member.
 35. Thefitting of claim 31, further comprising a plurality of grippingelements, each of the gripping elements coupled to one of the pluralityof secondary actuation members such that the plurality of grippingelements are moved axially towards the first end of the hollow body andradially inward towards the longitudinal axis of the hollow body from anopen position to an engaged position by actuating the primary actuationelement.
 36. The fitting of claim 31, wherein the first end of thehollow body includes a plurality of circumferentially spaced taperedtabs that converge towards the longitudinal axis at the first end,adjacent ones of the tabs being separated in the first circumferentialdirection by longitudinally extending slots and wherein the secondaryactuation members each extend through a respective one of thelongitudinally extending slots.
 37. The fitting of claim 31, wherein theprimary actuation element includes a plurality of sloped surfaces andeach one of the secondary actuation elements is engaged with arespective one of the plurality of sloped surfaces.
 38. The fitting ofclaim 31, wherein the primary actuation element is rotatably coupledwith the hollow body at the first end and rotation of the primaryactuation element in a first circumferential direction with respect tothe longitudinal axis of the hollow body draws the plurality ofsecondary actuation elements axially towards the opening at the firstend of the hollow body, thereby dragging the sealing member from an openposition to a sealing position.
 39. The fitting of claim 38, wherein thehollow body is coupled to the primary actuation element such that theprimary actuation element is rotated in the first circumferentialdirection by actuating at least one bolt.
 40. The fitting of claim 38,further comprising a bolt that extends from a first lug that extendsfrom the hollow body to a second lug that extends from the primaryactuation element, wherein the first and second lugs are positioned suchthat actuating the bolt causes the primary actuation element to rotatein the first circumferential direction.